Question

How is the lac operon regulated if the bacteria is put into an environment where there is excess amount of lactose and glucose at the same time. (10 pts)

7) From the previous question, how would the outcome change if the glucose and lactose amounts are very low? (10 pts)

Answer 1

# where there is excess amount of lactose and glucose at the same time, there will be low level of transcription of Lac Z, Lac Y and Lac A proteins, because higher level of glucose results into low level of cAMP. Hence, no activation of CAP binding protein and no enhancement of transcription.

#  How would the outcome change if the glucose and lactose amounts are very low, In this case, low level of glucose activates the higher level of cAMP which activates the CAP binding proteins. CAP binding protein binds the CAP region. However, due to low level of lactose, there is insufficient inhibition of Lac repressor protein. Hence, the transcription of Lac Z, Lac Y and Lac A will be very minimal or no transcription activity.

The detailed overview of Lac Operon is given below in the diagram